The brain is exceptionally rich in EFAs which make up over 20% of its dry weight and disorders in EFA metabolism may be expected to be reflected in mental disorders. We have previously discussed, for example in EP-A-0003407, a relation of schizophrenia to a deficit of 1-series prostaglandins (PGs) derived from dihomogamma-linolenic acid (DGLA) DGLA can be formed in the body from dietary linolerc acid via gamma-linolenic acid (GLA). Since the conversion of dietary linoleic acid to GLA may be restricted by a variety of factors we proposed that schizophrenia may be treated by GLA or DGLA alone or in combination with a variety of factors which may enhance the formation of 1-series PGs.
It has also been proposed that vitamin E may improve tardive dyskinesia (TD) on the grounds that anti-schizophrenic drugs may damage nerve endings by generating free radicals. Large doses of vitamin E, in excess of 400 IU per day, have been shown to improve the condition (Lohr J. B., Cadet, J. L., Lohr, M. A., "Alpha-Tocopherol in Tardive Dyskinesia" Lancet 1:913-4, 1987).